One man's steps to a greener lifestyle.

Ampera – selecting the charge current

My charger control project relies on the electric vehicle tracking the charge current set by the external EVSE / charger to maximise use of the solar panel output. Most vehicles would readily follow such a signal, but not the Ampera.

The Ampera is designed to default to charging at 6 Amps when using a Mode 2 cable (that is one with a household plug). Such a cable normally signals 10 Amps to the vehicle (a safety margin inside the UK’s 13 Amp domestic plugs) but the Ampera is designed to draw only 6 Amps by default.

To enable the Ampera to charge at 10 Amps the user has to permit this for every charging event individually.

This screen is reached by selecting Charging | Charge Current. Typically I would push the button in the driver’s door to open the flap over the charge port / vehicle inlet and then select the charge current via the touchscreen before leaving the vehicle.

Current limit from EVSE / Amps

Current drawn by vehicle / Amps - 6 Amp setting

Current drawn by vehicle / Amps - 10 Amp setting

6

6

6

10

6

10

16

14.3

14.3

With my Ampera, if the 10 Amp setting is not selected, then the EVSE / charger risks going into an error condition as the Programmable Logic Controller (PLC) expects the control signal from the ImmerSUN to turn off after a few minutes as rising vehicle current should cause the ImmerSUN relay output to cycle on and off around the available current limit. If the 10 Amp setting is effectively disabled then one might not reach the point at which the relay cycles within a reasonable time which the PLC will detect as an error.